With the advent of ionization type smoke detectors of the type shown in the Larry D. Larsen et al U.S. Pat. No. 3,832,552 issued Aug. 27, 1974, and the increased public awareness of the need of smoke and fire detectors in dwellings, a continual improvement in the design of such smoke detectors and the interconnecting systems associated with such detectors is being accomplished.
When a smoke detector of the type shown in the Larry D. Larsen et al patent is used in each of a plurality of areas, conventional circuit means are provided for interconnecting the annunciators or horns of the individual detectors so that upon the presence of an abnormal condition in one of the areas all of the horns will be operated to provide an alarm to the occupants in some remote area of the dwelling. Whenever a fire occurs in a dwelling having a plurality of areas, each having a smoke detector, upon the presence of an alarm by the sounding of the horns of each of the detectors, the occupant heretofore had no way of knowing whether the fire was in one area or another.
The present invention is concerned with a system of interconnecting individual abnormal condition responsive devices or smoke detectors so that upon the presence of smoke in one area, the operation of the horn is such that the occupant would be able to determine whether the abnormal condition is in the area in which he is located or in a remote area. Specifically, when a smoke detector in the area in which the smoke exists is energized, the horn is operated continuously and the detector has a horn energization circuit whereby by means of an interconnecting circuit the detectors of the remote areas will have their horns operate in an intermittent manner. The invention is disclosed in the following specification and drawing of which